Ultraviolet screen for fluorescent lamps



NIV 0 nh n C rl d U A D BSO-1.1

C-IW" 2,324,384

ULTRAVIOLET SCREEN Fon FLUORESCENT LAMPS July 13,'"1943,

Filed June 50, 1941 0R IN 24o/8.16

l l i l f Patented July 13; 1943 UNITE o STATES PATENT OFFICEULTRAVIOLET'SCREEN FR' FLUORESCENT IAMPS 7 Claims.

rLhis invention relatesto an ultra-violet. screen for a uorescent lampand has. for an object to providean. improved ultra-violetscreenl foruse on a fluorescent lamp, which screen' is of-'the type that itcan-be-easily-and quickly manually f, mani-pulaterlf to permit visiblellight to pass .therethrough or tolcut oi the visible light and taper.-mi-t. or-Iligpltrar vio lcnliehtlrimssiherethmueh;

A tur'ther object of the invention. is to provide a fixture for anultra-violet screen for a fluoo rescent light especially adaptable for.use'asan instrument lightperticularly onA aircraft, having means; forshading the-light from-'the opter.-` axtrsfeyes while making/theA sameeasily usable for the-.purpose intended., l5

4-Still a further object of this invention is to provideanxultra--violet screen and ar mounting` for the` screen-and aiuorescent lamp to be'used therewith, which can be inexpensivelymanufactured, easilyv assembled andd quickly disassembled 2H and.-reassembled'whenever necessary, for accessto. or replacement-of theuorescent bulb within thexture. ,i

With-.the-lituegoing and other objects in View; as will hereinafterbecome apparent, this' inven- 2;, tion`- comprises the combinations,constructions and arrangements-of parts hereinafter set'forth,disclosed, claimedand illustrated-'in the accompanying drawing.

In the drawing, j y Fig. `l .is apartlyv sectlonalviewpf: the` lamp,fixture and screen 'or this.V invention,v being subs stantially-on lineI-to fFig., 2:1 vf. f -`.:'ig. 2l is a front-view 'of the-.lamp-rand'xture looking. in they directionof thearrowlon Fig.-k;

Fig..3isa perspective view of' the'screen-hold- 'l ing rim; and l 4 is aperspective view of the amplementary units .formi-ng the screen. p

There isshown at I0 the' fixture of .this iri 4! vention comprising amounting bracketV II on Whichis vadlustablysecured the fixture body l2;WithinV the xture body I2 is provided va lamp socket I 3'for holding afluorescentflamp i4 therewithin, ythe inner surface f5.0f the xture body4: l2, being provided with the customary polished? reecting surface. Theopen end of. the' xture bodyv I2, throughwh-ich the lampl isv to be in-4serted, is provided with a reduced neck I6 so as to receive thereon thecomplementary counter- :in bore I1 of a screen-holding rim I3.

This screen-holding rim consists of two rings 2li and 2|, the ring 2l)Ahaving the aforementioned counterbore I'I at one edge thereof and; beingprovidedx at itsl other edge with a reduced:| mi

( Cl. Z110-8.16)

neck 22., to rotatably receiveithe other ring 2I thereon. Extendingoircumferentially aboutl and through reduced neck 22 are twooppositelydisposed slots-23, each slot extending 99 degrees thereabout.4Projecting-through the ring 2I are two oppositely disposed rivets 24,one rivet extending into each of the slots 23. As will be apparent,these rivets 24 and slots 23 serve to limit the rotation of. the ring 2lon the ring 20 to 90f-degrees, and at thesame time preventlongitudinalseparationofthe-two rings 20 and 2l. Thecounterbore I1 ofl2D isprovided vwith two longitudinal edge-.slots 2B (which may beangular or. bayonet .j oint. vtypeslots, if, desired) which cooperatewith stud screws 21 in securing the4 rim I8 on the fixture .body I2. y

The ultra-violet screen 28 consists cf two iden.- ticall units 3U'molded and ground to the form shown. Each unitl is made of suitablematerial capable of transmitting ultra-violet light therethrough, onesuch suitable ,material on the market being commercially, known asCorex." Each unit 30 consists of a rounddisc of proper thickness, andeach disc is provided with` one or two notches. 3I and also with twodiametrically opposed sectcr-shaped. openings 32'. Each sector is of 90degrees, but its right angle 33 is slightly displaced along a'radiusfrom the center, so that, when the two units or discs 3U are broughttogether in face to face relation, they may, by relative rotation, oneto the other, be 4brought into af position with'their openings incoincidence, capableof transmitting visible light therethrough, or berotated 90 degrees, one to the other, to block oil* all visible light,but transmit ultra-Violet light. w

To properly mount these two discs 30 for such controllable vrelativerotation,v the reduced neck 22 of ring 20 is provided with one or twoexten-ding lingers 34 coinciding in location withthe notches 3'I of onedisc 30, so that, when one disc 30- is placed into the rim I8, thefinger 34 holds the rst disc 30 against rotation relative to the ring22. Then the second disc is placed into rim I8 against the rst disc, andstuds or rivets 35, suitably located about the ring 2I, extend'into thenotches 3I of the second disc 30. Next an annular spring 3G is insertedwithin an annular'l notch within a iiange 31 on the edge of ring 2| tohold the second or outer disc flush against the rst or inner disc.

In operation, with the discs 30 of the ultraviolet screen 28 mounted inthe rim I8 and on the. fixture body I2 with the fluorescent lamp I4 inaction, the operator may have visible or ultraviolet light at will bymerely grasping the knurling 25 on ring 2l and rotating it a quarterturn in either direction. He may easily direct the light by turning thefixture about on its universal mounting 38.

Obviously, if desired, the sector-shaped openings 32 may be filled withany desired transparent visible and ultra-violet light transmittingmaterial, either a suitable glass or a suitable plastic c osition. Inaddition, if desired, a- Fa'l'nlisqxtlment to both visible andultraviolet light may be placed between the spring 3`|- and the outerdisc 30, so as to prevent the possibility of moisture getting into thefixture body to affect the reflecting surface l5.

While the device has been shown and the structure has been described indetail, it is obvious that this invention is not to be consideredlimited to the exact form disclosed and that changes may be made thereinwithin the scope of what is claimed without departing from the spirit ofthe invention. v

Having thus set forth and disclosed the nature of this invention, whatis claimed is:

1. An ultra-violet light comprising a xture body adapted to receive anultra-violetI and visible light producting lamp therein and a screenthrough whichY the beams from the lamp may pass, said screen beingcapable of optionally transmittingr either visible lightA orultra-violet light without any visible light, said screen comprisingapair of substantially identical circular soliddisc unit, each of saidunits having visible light transmitting sector shaped openingstherethrough, said openingsoccupying less than onehalf of the area ofeach unit, and means for mounting said units in said xture body face toface-whereby one of said units may be peripherally rotated relative tothe other of said units to bring the openings in each unit eitherintoalignment to transmit visible light or out of alignment to block olfvisible light whereby only ultra-violet light may pass therethrough. 2.An ultra-violet light comprising a fixture body adapted to receive anultra-violet and visible light producing lamp therein and a screenthrough which the beams from the lamp may pass, said screen beingcapable of optionally transmitting either visible light or ultra-violetlight without any visible light, said screen comprising a pair ofsubstantially identical circular solid disc units, each of said unitshaving. visible light transmitting sector shaped. openings therethrough,said openings occupying less than onehalf of the area of leach unit, andmeans for mounting said units in said xture body face to face wherebyAone of said unitsmay be peripherally rotated relative to the other ofsaid units to bring the openings in each'uniteither inta alignment totransmit visible light or out of alignment to block oif visible lightwhereby only ultra-violet' light may pass therethrough, said mountingmeans comprising means: for securing one of said units againstperipheral rotation, and means for supporting the other of saidunitsface to facewith the rst of said units for peripheral rotation, saidsupporting means having means on the periphery thereof for manualmanipulation of said peripherally rotatable unit.

3. An ultra-violet light and visible light transmitting screencomprising a pair of substantially identical solid screen discs, eachmade of ultraviolet transmitting and visible light blocking material,each of said discs having visible light transmitting sector shapedopenings therethrough, said openings excluding the centers of saiddiscs, said openings comprising less than one-half the area of saiddiscs, and means for mounting said discs in face to face juxtapositionfor relative rotation of one of said discs to the other of said discs,whereby the openings in said discs may be brought into alignment totransmit visible light or may be moved completely out of alignment toblock oi visible lightand transmit only ultra-violet light.

4. An ultra-violet light and visible light transmitting screencomprising a pair of substantially videntical screen discs, each made ofultra-violet transmitting and visible light blocking material, each ofsaid discs having visible light transmitting openings therethrough, saidopenings excluding the centers of said discs, said openings comprisingless than one-half the area of said discs, and means for mounting saiddiscs in juxtaposition-for relative rotation of one of said discs tothe4 other of said discs, whereby the openings in said discs may bevbrought into alignment to transmit visibleflight or may be movedcompletely out offalignment to block oil visible light and transmit onlyultra-violet light, said mounting meansy including means for holding onedisc againstv rotation and manually manipulatable means for facilitatingthe'rotation of the other disc;

5. An ultra-violet light and visible light transmitting screencomprising a pair of substantially identical screen discs, each made ofultra-violet transmitting andA visible light blocking material, each ofsaid discs having. visible light transmitting openings therethrough,said openings excludingithe centers of' said discs, said openingscomprising less than one-half the area of said discs, means for mountingsaid discs in juxtaposition for relative rotation of one of said discsto the other of said discs, whereby the openings in said discs may be-brought into alignment toA transmit visible light or may be movedcompletely out of alignment to block oil. visible light and transmitonly ultra-violet light, said mounting means including peripheralirregularities on said discs,'and means on said mounting meanscooperating with said peripheral irregularities.

6. A lamp xture including an ultra-violet light and visible lighttransmitting screen comprising a pair of substantially identical screendiscs, each made of ultra-violet transmitting and visible light blockingmaterial, each of said discs having visible light transmitting openingstherethrough, said openings excluding the centers of said'discs, saidopenings comprising less than one-half the area of said discs, means formounting said discs in juxtaposition for relative rotation-of one ofsaid discs tothe other of said discs, whereby the openings in said discsmay be brought into alignment to transmit visible light or may be movedcompletely out of alignment to block oil visible light' and transmitonly ultra-violet light, said mount` ing means including peripheralirregularities on said discs, a detachable lamp :lixture rim, said rimcomprising a pair of relatively rotatable rings, cooperating means onsaid rings permitting limited relative rotation thereof one to theother, and means on saidrings cooperating with saidv disc peripheralirregularities causing each disc to be xed relative to its ring.

'7. A lamp fixture including an ultra-violet light and visible lighttransmittingscreen comprising a pair `of substantially identical screendiscs, each made of ultra-violet transmitting and vislble OUCH bll HUUIHlight blocking material, each of said discs having visible lighttransmitting openings therethrough, said openings excluding the centersof said discs, said openings comprising less than one-half the area ofsaid discs, means for mounting said discs in juxtaposition for relativerotation of one of said discs to the other of said discs, whereby theopenings in said discs may be brought into alignment to transmit visiblelight or may be moved completely out of alignment to block off visiblelight and transmit only ultra-violet light, said mounting meansincluding peripheral irregularities on said discs, a detachable lampxture rim, said rim comprising a pair of relatively rotatable rings,cooperating means on said rings permitting limited relative rotationthereof one to the other, and means on said rings cooperating with saiddisc peripheral irregularities causing each disc to be xed relative toits ring, said disc cooperating means comprising protruding iinger meanson one ring and protruding stud means on the l0 other ring.

WARREN G. GRIMES.

